As of 2010, heart disease was is the leading cause of death in the United States, according to the Centers for Disease Control and Prevention. Coronary artery disease, or CAD, is the most common form of heart disease in the U.S. Coronary artery disease is a condition in which plaque builds up on the inside of the blood vessels that supply blood and oxygen to the heart. Chronic coronary disease can lead to sudden, acute medical conditions. Acute coronary disease events like heart attacks can happen when plaque narrows the artery until it is completely blocked, or the blockage may be the result of plaque breaking off and clogging the artery.
Anatomy
Blood supplies oxygen to the muscles in the body. All muscles, including the heart, must have good blood supply or the tissue will become starved of oxygen and begin to die. If the heart does not have enough oxygen, the person may suffer chest pains or even a heart attack. The coronary arteries supply the heart with the blood it needs unless these vessels are blocked by plaque or blood clots.
Cause
MayoClinic.com states that coronary artery disease begins as early as childhood, starting as damage to the artery. Plaque, which is made of fat, cholesterol, calcium and other substances, accumulates near damaged areas. This accumulation narrows the artery and blood flow to the heart is decreased. Furthermore, high blood pressure can cause plaque to become dislodged from the artery, where it flows freely until potentially becoming trapped near the heart. Blood flow may be partially or completely blocked by plaque.
Risk Factors
Coronary artery disease has several causes, including smoking, high blood pressure, high cholesterol and diabetes. Getting older increases the risk of developing coronary artery disease. Men suffer CAD more often than woman, although, as she ages, a woman's risk grows to equal that of men. Family history increases the odds of suffering coronary artery disease. Obesity, inactivity and stress increase risk. The slow progression of chronic coronary disease may lead to a sudden acute medical crisis, such as heart attack.
Symptoms
The most common symptom of coronary artery disease is angina, which causes chest discomfort or pain because the heart muscle is being starved of oxygen. Angina is an acute coronary event. A heart attack can be the first sign of coronary heart disease for some people. The patient may say it feels like someone is sitting on his chest or squeezing his heart. This may be accompanied by shortness of breath and nausea. These symptoms may grow worse with exertion or stress.
Diagnosis
A nurse will take a patient's vital signs, including blood pressure, as well as gather a detailed medical history. The physician will perform a thorough examination and order blood tests and other tests to give her a clearer picture of the patient's heart health. These tests might include an EKG, which measures the electrical signals in the heart; abnormalities may indicate a problem with blood flow to the heart. An echocardiogram takes pictures of the heart to see if all parts of the heart are functioning. A CT scan helps a physician see the arteries; dye may be injected into the bloodstream to enhance visualization. Cardiac catheterization may be ordered. This test begins by injecting a dye into the patient's bloodstream. A long, flexible tube is inserted, usually in the leg, and threaded through the arteries to the heart. If blockage is seen, a balloon may be inflated to open the blocked blood vessel.
Treatment
Treatment includes lifestyle changes, such as exercise, a healthy diet, quitting smoking, reducing stress and losing weight. Drugs like statins can help lower cholesterol. Aspirin thins the blood, preventing the formation of clots which may block arteries and cause heart attacks. Beta-blockers slow the heart rate and reduce blood pressure; these decrease the amount of pressure the blood exerts on plaque lining the arterial walls, reducing the risk of plaque rupture. Nitroglycerin relieves chest pain by dilating the coronary arteries. Other prescription drugs like ACE-inhibitors and calcium channel blockers work by reducing blood pressure.
